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1.
Anal Chem ; 90(1): 872-880, 2018 01 02.
Artículo en Inglés | MEDLINE | ID: mdl-29193960

RESUMEN

Electrical lysis of mammalian cells has been a preferred method in microfluidic platforms because of its simple implementation and rapid recovery of lysates without additional reagents. However, bacterial lysis typically requires at least a 10-fold higher electric field (∼10 kV/cm), resulting in various technical difficulties. Here, we present a novel, low-field-enabled electromechanical lysis mechanism of bacterial cells using electroconvective vortices near ion selective materials. The vortex-assisted lysis only requires a field strength of ∼100 V/cm, yet it efficiently recovers proteins and nucleic acids from a variety of pathogenic bacteria and operates in a continuous and ultrahigh-throughput (>1 mL/min) manner. Therefore, we believe that the electromechanical lysis will not only facilitate microfluidic bacterial sensing and analysis but also various high-volume applications such as the energy-efficient recovery of valuable metabolites in biorefinery pharmaceutical industries and the disinfection of large-volume fluid for the water and food industries.


Asunto(s)
Bacteriólisis , Técnicas Electroquímicas/métodos , Técnicas Analíticas Microfluídicas/métodos , Técnicas Electroquímicas/instrumentación , Escherichia coli K12/química , Fenómenos Mecánicos , Membranas Artificiales , Técnicas Analíticas Microfluídicas/instrumentación , Mycobacterium smegmatis/química
2.
Planta Med ; 83(3-04): 224-231, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27420352

RESUMEN

Puerarin is a major isoflavone glycoside from the root of Pueraria lobata. It has been reported that puerarin can protect neurons from oxidative stress-induced apoptosis. Emerging evidence suggests that oxidative damage is associated with Aß-induced neuronal death. In the current study, we evaluated the effect of puerarin on Alzheimer's disease induced by Aß and explored the potential mechanisms underlying this effect. We found that the escape latency of the Morris water maze was decreased in groups treated with puerarin compared to the model group (p < 0.01). In addition, there were significant differences between treated groups and the model group mice in a Y-maze test (p < 0.01). Furthermore, puerarin recovered the levels of brain-derived neurotrophic factor, phosphorylated tau, malondialdehyde, acetylcholine esterase, glycogen synthase kinase-3beta, and the activity of superoxide dismutase to some extent in the hippocampus and cerebral cortex. Shrinkage of nuclei and swollen and eccentrically dispersed neuronal bodies were observed in the hippocampus of Aß-treated mice. These data demonstrate that puerarin might protect against cognitive deficits, oxidative stress, and neurodegeneration induced by Aß1-42.


Asunto(s)
Isoflavonas/farmacología , Aprendizaje por Laberinto/efectos de los fármacos , Memoria/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Enfermedad de Alzheimer/inducido químicamente , Enfermedad de Alzheimer/tratamiento farmacológico , Péptidos beta-Amiloides/administración & dosificación , Péptidos beta-Amiloides/metabolismo , Animales , Apoptosis/efectos de los fármacos , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/metabolismo , Modelos Animales de Enfermedad , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Isoflavonas/química , Masculino , Ratones , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Estrés Oxidativo/efectos de los fármacos , Fragmentos de Péptidos/administración & dosificación , Superóxido Dismutasa/metabolismo
3.
Anal Chem ; 88(23): 11750-11757, 2016 12 06.
Artículo en Inglés | MEDLINE | ID: mdl-27797505

RESUMEN

Leukocytes are the essential cells of the immune system that protect the human body against bacteria, viruses, and other foreign invaders. Secretory products of individual leukocytes, such as matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase (ADAMs), are critical for regulating the inflammatory response and mediating host defense. Conventional single cell analytical methods, such as flow cytometry for cellular surface biomarker studies, are insufficient for performing functional assays of the protease activity of individual leukocytes. Here, an integrated continuous-flow microfluidic assay is developed to effectively detect secretory protease activity of individual viable leukocytes. Leukocytes in blood are first washed on-chip with defined buffer to remove background activity, followed by encapsulating individual leukocytes with protease sensors in water-in-oil droplets and incubating for 1 h to measure protease secretion. With this design, single leukocyte protease profiles under naive and phorbol 12-myristate 13-acetate (PMA)-stimulated conditions are reliably measured. It is found that PMA treatment not only elevates the average protease activity level but also reduces the cellular heterogeneity in protease secretion, which is important in understanding immune capability and the disease condition of individual patients.


Asunto(s)
Leucocitos/citología , Leucocitos/enzimología , Técnicas Analíticas Microfluídicas , Péptido Hidrolasas/metabolismo , Análisis de la Célula Individual , Supervivencia Celular , Difusión , Diseño de Equipo , Humanos , Programas Informáticos
4.
Annu Rev Biomed Eng ; 17: 1-34, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26194427

RESUMEN

Microfluidic cell-separation technologies have been studied for almost two decades, but the limited throughput has restricted their impact and range of application. Recent advances in microfluidics enable high-throughput cell sorting and separation, and this has led to various novel diagnostic and therapeutic applications that previously had been impossible to implement using microfluidics technologies. In this review, we focus on recent progress made in engineering large-volume microfluidic cell-sorting methods and the new applications enabled by them.


Asunto(s)
Separación Celular/métodos , Técnicas Analíticas Microfluídicas/métodos , Ingeniería Biomédica , Biomimética , Transfusión Sanguínea , Ciclo Celular , Separación Celular/instrumentación , Centrifugación/métodos , Diseño de Equipo , Ensayos Analíticos de Alto Rendimiento/instrumentación , Ensayos Analíticos de Alto Rendimiento/métodos , Humanos , Hidrodinámica , Riñones Artificiales , Dispositivos Laboratorio en un Chip , Células Neoplásicas Circulantes/patología , Recuperación de Sangre Operatoria , Sepsis/sangre , Sepsis/terapia
5.
Opt Lett ; 41(10): 2141-4, 2016 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-27176947

RESUMEN

We investigate the broadband anti-Stokes emission (BASE) from Yb3+-doped crystals with a laser diode (LD) pumping at 940 nm. Our experiment reveals that Yb3+-doped crystals with random cracks are able to generate bright BASE at room temperature and atmospheric pressure. By examining the various characteristics of the crystals and the emitted light, we supply a theory for interpreting the underlying physics for this variety of BASE. In particular, we take into consideration the effects of energy migration, avalanche process, and charge-transfer luminescence. This represents the first time, to the best of our knowledge, that BASE was obtained from Yb3+-doped bulk crystals with a high optical-optical efficiency.

6.
J Am Chem Soc ; 137(1): 259-66, 2015 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-25506785

RESUMEN

Although numerous studies have been devoted to the charge transfer through double-stranded DNA (dsDNA), one of the major problems that hinder their potential applications in molecular electronics is the fast deprotonation of guanine cation (G(+•)) to form a neutral radical that can cause the termination of hole transfer. It is thus of critical importance to explore other DNA structures, among which G-quadruplexes are an emerging topic. By nanosecond laser flash photolysis, we report here the direct observation and findings of the unusual deprotonation behavior (loss of amino proton N2-H instead of imino proton N1-H) and slower (1-2 orders of magnitude) deprotonation rate of G(+•) within G-quadruplexes, compared to the case in the free base dG or dsDNA. Four G-quadruplexes AG3(T2AG3)3, (G4T4G4)2, (TG4T)4, and G2T2G2TGTG2T2G2 (TBA) are measured systematically to examine the relationship of deprotonation with the hydrogen-bonding surroundings. Combined with in depth kinetic isotope experiments and pKa analysis, mechanistic insights have been further achieved, showing that it should be the non-hydrogen-bonded free proton to be released during deprotonation in G-quadruplexes, which is the N2-H exposed to solvent for G bases in G-quartets or the free N1-H for G base in the loop. The slower N2-H deprotonation rate can thus ensure less interruption of the hole transfer. The unique deprotonation features observed here for G-quadruplexes open possibilities for their interesting applications as molecular electronic devices, while the elucidated mechanisms can provide illuminations for the rational design of G-quadruplex structures toward such applications and enrich the fundamental understandings of DNA radical chemistry.


Asunto(s)
ADN/química , G-Cuádruplex , Guanina/química , Protones , Cationes/química , Radicales Libres/química
7.
Sci Total Environ ; 950: 175391, 2024 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-39122040

RESUMEN

The increasing use of antibiotics has attracted widespread attention to their environmental risks. However, the phototoxicity of sulfonamide antibiotics to plants remain unclear. In this study, the mechanism of the effect of sulfamethoxazole on photosynthesis of pakchoi cabbage (Brassica rapa var. chinensis) was investigated. The results showed that sulfamethoxazole inhibited the growth of pakchoi cabbage and produced photosynthetic toxicity. The growth inhibition rates increased with concentration, the root and shoot weight were 76.02 % and 47.04 % of the control, respectively, with stay-greens phenomenon in 4 mg·L-1 sulfamethoxazole treatment. Chlorophyll precursors (protoporphyrin IX (Proto IX), Mg-proto IX, and protochlorophyllide (Pchlide), 5-aminolevulinic acid (ALA), and porphobilinogen (PBG)) were 1.38-, 1.26-, 1.12-, 1.71-, and 0.96-fold of the control, respectively; photosynthetic pigments (chlorophyll a, chlorophyll b, and carotenoids) were 1.26-, 1.39-, and 1.03-fold of the control, respectively. Respiration rate was 271.42 % of the control, whereas the net photosynthetic rate was 50.50 % of the control. The maximum photochemical quantum yield of PSII (Fv/Fm), the actual photosynthetic efficiency (Y(II)), the quantum yield of non-regulated energy dissipation (Y(NO)), the apparent electron transfer efficiency of PSII (ETR) under actual light intensity were affected, and chloroplast swelling was observed. Proteomic analysis showed that photosynthesis-related pathways were significantly up-regulated, biological processes such as light response, carbohydrates, and reactive oxygen species were activated. Metabolomic analysis revealed that the tricarboxylic acid cycle (TCA cycle) and carbohydrate catabolism were stimulated significantly (p < 0.05), sugars and amino acids were increased to regulate and enhance the resilience of photosynthesis. While folate biosynthesis and ribosomal pathways were significantly down-regulated, the synthesis and translation processes of amino acids and nucleotides were inhibited.


Asunto(s)
Brassica rapa , Fotosíntesis , Plantones , Sulfametoxazol , Sulfametoxazol/toxicidad , Brassica rapa/efectos de los fármacos , Brassica rapa/fisiología , Fotosíntesis/efectos de los fármacos , Plantones/efectos de los fármacos , Clorofila/metabolismo
8.
J Comput Biol ; 31(9): 871-885, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39117342

RESUMEN

Recent technological advancements have enabled spatially resolved transcriptomic profiling but at a multicellular resolution that is more cost-effective. The task of cell type deconvolution has been introduced to disentangle discrete cell types from such multicellular spots. However, existing benchmark datasets for cell type deconvolution are either generated from simulation or limited in scale, predominantly encompassing data on mice and are not designed for human immuno-oncology. To overcome these limitations and promote comprehensive investigation of cell type deconvolution for human immuno-oncology, we introduce a large-scale spatial transcriptomic deconvolution benchmark dataset named SpatialCTD, encompassing 1.8 million cells and 12,900 pseudo spots from the human tumor microenvironment across the lung, kidney, and liver. In addition, SpatialCTD provides more realistic reference than those generated from single-cell RNA sequencing (scRNA-seq) data for most reference-based deconvolution methods. To utilize the location-aware SpatialCTD reference, we propose a graph neural network-based deconvolution method (i.e., GNNDeconvolver). Extensive experiments show that GNNDeconvolver often outperforms existing state-of-the-art methods by a substantial margin, without requiring scRNA-seq data. To enable comprehensive evaluations of spatial transcriptomics data from flexible protocols, we provide an online tool capable of converting spatial transcriptomic data from various platforms (e.g., 10× Visium, MERFISH, and sci-Space) into pseudo spots, featuring adjustable spot size. The SpatialCTD dataset and GNNDeconvolver implementation are available at https://github.com/OmicsML/SpatialCTD, and the online converter tool can be accessed at https://omicsml.github.io/SpatialCTD/.


Asunto(s)
Transcriptoma , Microambiente Tumoral , Microambiente Tumoral/genética , Humanos , Transcriptoma/genética , Perfilación de la Expresión Génica/métodos , Biología Computacional/métodos , Análisis de la Célula Individual/métodos , Ratones , Animales , Neoplasias/genética , Neoplasias/patología , Algoritmos , Programas Informáticos , Redes Neurales de la Computación
9.
Anal Chem ; 85(24): 11695-9, 2013 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-24251795

RESUMEN

In this paper, we evaluate the strategy of using self-assembled microbeads to build a robust and tunable membrane for free-flow zone electrophoresis in a PDMS microfluidic chip. To fabricate a porous membrane as a salt bridge for free-flow zone electrophoresis, we used silica or polystyrene microbeads between 3-6 µm in diameter and packed them inside a microchannel. After complete evaporation, we infiltrated the porous microbead structure with a positively or negatively charged hydrogel to modify its surface charge polarity. Using this device, we demonstrated binary sorting (separation of positive and negative species at a given pH) of peptides and dyes in standard buffer systems without using sheath flows. The sample loss during sorting could be minimized by using ion selectivity of hydrogel-infiltrated microbead membranes. Our fabrication method enables building a robust membrane for pressure-driven free-flow zone electrophoresis with tunable pore size as well as surface charge polarity.


Asunto(s)
Dimetilpolisiloxanos , Electroforesis/métodos , Membranas Artificiales , Técnicas Analíticas Microfluídicas/métodos , Microesferas , Dióxido de Silicio/química , Hidrodinámica
10.
J Phys Chem A ; 117(33): 7767-75, 2013 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-23869950

RESUMEN

The o-hydroxycinnamic derivatives represent efficient caged compounds that can realize quantification of delivery upon uncaging, but there has been lack of time-resolved and mechanistic studies. We used time-resolved infrared (TRIR) spectroscopy to investigate the photochemical uncaging dynamics of the prototype o-hydroxycinnamic compound, (E)-3-(2-hydroxyphenyl)-acrylic acid ethyl ester (HAAEE), leading to coumarin and ethanol upon uncaging. Taking advantage of the specific vibrational marker bands and the IR discerning capability, we have identified and distinguished two key intermediate species, the cis-isomers of HAAEE and the tetrahedral intermediate, in the transient infrared spectra, thus providing clear spectral evidence to support the intramolecular nucleophilic addition mechanism following the trans-cis photoisomerization. Moreover, the product yields of coumarin upon uncaging were observed to be greatly affected by the solvent polarity, suppressed in CH2Cl2 but enhanced in D2O/CH3CN with the increasing volume ratio of D2O. The highly solvent-dependent behavior indicates E1 elimination of the tetrahedral intermediate to give rise to the final uncaging product coumarin. The photorelease rate of coumarin was directly characterized from TRIR (3.6 × 10(6) s(-1)), revealing the promising application of such o-hydroxycinnamic compound in producing fast alcohol jumps. The TRIR results provide the first time-resolved detection and thus offer direct dynamical information about this photochemical uncaging reaction.


Asunto(s)
Ácidos Cumáricos/química , Cumarinas/síntesis química , Cumarinas/química , Etanol/síntesis química , Etanol/química , Estructura Molecular , Procesos Fotoquímicos , Espectrofotometría Infrarroja , Factores de Tiempo , Rayos Ultravioleta
11.
Appl Microbiol Biotechnol ; 97(17): 7669-77, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23224405

RESUMEN

Granulysin is a cytolytic, proinflammatory protein produced by human cytolytic T-lymphocytes and natural killer cells. Granulysin has two stable isoforms with molecular weight of 9 and 15 kDa; the 9-kDa form is a result of proteolytic maturation of the 15-kDa precursor. Recombinant 9-kDa granulysin exhibits cytolytic activity against a variety of microbes, such as bacteria, parasites, fungi, yeast and a variety of tumor cell lines. However, it is difficult to produce granulysin in large quantities by traditional methods. In this study, we developed a simple and robust fed-batch fermentation process for production and purification of recombinant 9- and 15-kDa granulysin using Pichia pastoris in a basal salt medium at high cell density. The granulysin yield reaches at least 100 mg/l in fermentation, and over 95 % purity was achieved with common His-select affinity and ion exchange chromatography. Functional analysis revealed that the yeast-expressed granulysin displayed dose-dependent target cytotoxicity. These results suggest that fermentation in P. pastoris provides a sound strategy for large-scale recombinant granulysin production that may be used in clinical applications and basic research.


Asunto(s)
Antígenos de Diferenciación de Linfocitos T/metabolismo , Técnicas de Cultivo Celular por Lotes/métodos , Pichia/metabolismo , Antígenos de Diferenciación de Linfocitos T/química , Antígenos de Diferenciación de Linfocitos T/genética , Antígenos de Diferenciación de Linfocitos T/aislamiento & purificación , Reactores Biológicos/microbiología , Fermentación , Peso Molecular , Pichia/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo
12.
Nurse Educ Today ; 122: 105738, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36731246

RESUMEN

BACKGROUND: Medical and nursing students will play an essential role in delivering palliative care in the future. Death education is important in preparing them for future palliative care, however, little is known about students education needs and how death attitudes affect such needs in Mainland China. OBJECTIVES: The purpose of this survey was to investigate the death education needs of medical and nursing students and to evaluate the impact of death attitudes on death education needs. DESIGN: Multi-center, cross-sectional survey. SETTINGS: Fourteen medical and nursing colleges & universities in Hunan, Sichuan, Liaoning, Guangdong, Shandong, and Shanxi provinces in China. PARTICIPANTS: The sample included 1044 medical and nursing students from six provinces. METHODS: In this multi-center cross-sectional study, all data were collected through an online questionnaire that included demographic information and questions on death-related experiences. In addition, the Death Attitude Profile-Revised and the Death Education Needs Scale were used to evaluate students' death attitudes and death education needs , respectively. RESULTS: The students had a mean death education needs score of 38.85 ± 7.25 (range: 10-50), yet only 20.9 % of them had received palliative care-related training. Being female (B:3.869, 95 % CI:2.849-4.889), fear of death (B:0.119, 95 % CI:0.005-0.232), and neutral acceptance (B:0.787, 95 % CI:0.638-0.936) were associated with higher death education needs, while death avoidance (B: -0.226, 95 % CI: -0.368 ~ -0.083), approach acceptance (B: -0.126, 95 % CI: -0.215 ~ -0.036), and escape acceptance (B: -0.198, 95 % CI: -0.322 ~ -0.073) were associated with lower death education needs. CONCLUSIONS: The high level of death education needs and low training rate in palliative care among medical and nursing students in mainland China indicates a gap that needs to be addressed. Students' death education needs were affected by gender and death attitudes, which provides implications for the future development of palliative care training models.


Asunto(s)
Estudiantes de Medicina , Estudiantes de Enfermería , Humanos , Femenino , Masculino , Estudios Transversales , Actitud del Personal de Salud , Cuidados Paliativos , Encuestas y Cuestionarios
13.
Anal Chem ; 84(21): 9324-31, 2012 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-23025404

RESUMEN

Inertial microfluidics has recently drawn wide attention as an efficient, high-throughput microfluidic cell separation method. However, the achieved separation resolution and throughput, as well as the issues with cell dispersion due to cell-cell interaction, have appeared to be limiting factors in the application of the technique to real-world samples such as blood and other biological fluids. In this paper, we present a novel design of a spiral inertial microfluidic (trapezoidal cross-section) sorter with enhanced separation resolution and demonstrate its ability in separating/recovering polymorphonuclear leukocytes (PMNs) and mononuclear leukocytes (MNLs) from diluted human blood (1-2% hematocrit) with high efficiency (>80%). PMNs enriched by our method also showed negligible activation as compared to original input sample, while the conventional red blood cell (RBC) lysis method clearly induced artificial activation of the sensitive PMNs. Therefore, our proposed technique would be a promising alternative to enrich/separate sensitive blood cells for therapeutic or diagnostic applications.


Asunto(s)
Separación Celular/métodos , Leucocitos Mononucleares/citología , Neutrófilos/citología , Separación Celular/instrumentación , Diseño de Equipo , Eritrocitos/citología , Humanos , Técnicas Analíticas Microfluídicas , Fenotipo
14.
Carbohydr Polym ; 285: 119205, 2022 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-35287845

RESUMEN

Alzheimer's disease (AD) is a neurodegenerative disease characterized by memory loss and cognitive impairments. Amyloid-ß (Aß) deposition and neurotoxicity play important roles in AD. It has been widely reported that heparan sulfate (HS) proteoglycans play a nonnegligible role in the release, uptake and misfolding of Aß, resulting in the discovery of HS as a therapeutic drug for AD. In this manuscript, HS from porcine mucosa could promote Aß fibrosis and improve the cognitive defects of APPswe/PS1ΔE9 mice. Furthermore, HS enhanced the phagocytosis of neutrophils to clear Aß1-42 from peripheral circulation, reduced peripheral Aß1-42 flow to the brain and increased Aß efflux from the brain. Therefore, the deposition of Aß plaques in the brain was decreased. In addition, HS alleviated neutrophil infiltration and reduced neuroinflammation. Conclusively, HS is a promising neuroprotective candidate for AD treatment.


Asunto(s)
Enfermedad de Alzheimer , Enfermedades Neurodegenerativas , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/metabolismo , Animales , Encéfalo/metabolismo , Modelos Animales de Enfermedad , Heparitina Sulfato , Ratones , Ratones Transgénicos , Membrana Mucosa/metabolismo , Enfermedades Neurodegenerativas/patología , Porcinos
15.
Int J Biol Macromol ; 206: 823-836, 2022 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-35307462

RESUMEN

Amyloid-ß (Aß) deposition and neurotoxicity play an important role in Alzheimer's disease (AD). Notably, the nonnegligible role of endogenous heparan sulfate (HS) in the release, uptake and misfolding of Aß sheds light on the discovery of HS as an effective drug for AD. In this work, the effects of HS from porcine mucosa (PMHS) on Aß1-42-induced neurotoxicity were investigated both in vitro and in vivo. The in vitro AD model was established in SH-SY5Y via treatment with oligomeric Aß1-42, and the in vivo AD model was established by intracerebroventricular injection of Aß1-42 to KM mice. The results showed that in vitro, PMHS could ameliorate the inflammation and apoptosis response of SH-SY5Y cells induced by Aß1-42; in vivo, PMHS could not only improve the cognitive impairment induced by Aß1-42 but also inhibit neuroinflammation and apoptosis in the brain. Furthermore, PMHS lowered the levels of Aß1-42 in the peripheral circulation and brain by improving the phagocytosis function of neutrophils. This is the first report that PMHS enhances the phagocytosis function of neutrophils to alleviate Aß-induced neurotoxicity. Moreover, our work verified the feasibility of peripheral Aß clearance for improving neurotoxicity. Conclusively, we believe that PMHS could be developed into neuroprotective drugs for AD.


Asunto(s)
Enfermedad de Alzheimer , Fragmentos de Péptidos , Enfermedad de Alzheimer/inducido químicamente , Enfermedad de Alzheimer/tratamiento farmacológico , Péptidos beta-Amiloides/efectos adversos , Animales , Cadáver , Heparitina Sulfato/farmacología , Ratones , Membrana Mucosa , Fragmentos de Péptidos/efectos adversos , Porcinos
16.
ACS Appl Mater Interfaces ; 14(38): 42963-42975, 2022 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-36111385

RESUMEN

The harsh conditions of the gastrointestinal tract limit the potential health benefits of oral probiotics. It is promising that oral bioavailability is improved by strengthening the self-protection of probiotics. Here, we report the encapsulation of a probiotic strain by endogenous production of hyaluronan to enhance the effects of oral administration of the strain. The traditional probiotic Streptococcus thermophilus was engineered to produce hyaluronan shells by using traceless genetic modifications and clustered regularly interspaced short palindromic repeat interference. After oral delivery to mice in the form of fermented milk, hyaluronan-coated S. thermophilus (204.45 mg/L hyaluronan in the milk) exhibited greater survival and longer colonization time in the gut than the wild-type strain. In particular, the engineered probiotic strain could also produce hyaluronan after intestinal colonization. Importantly, S. thermophilus self-encapsulated with hyaluronan increased the number of goblet cells, mucus production, and abundance of the microorganisms related to the biosynthesis of short-chain fatty acids, resulting in the enhancement of the intestinal barrier. The coating formed by endogenous hyaluronan provides an ideal reference for the effective oral administration of probiotics.


Asunto(s)
Probióticos , Streptococcus thermophilus , Animales , Ácidos Grasos Volátiles , Ácido Hialurónico , Ratones , Leche , Streptococcus thermophilus/genética
17.
Nat Biotechnol ; 40(12): 1794-1806, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36203011

RESUMEN

Resolving the spatial distribution of RNA and protein in tissues at subcellular resolution is a challenge in the field of spatial biology. We describe spatial molecular imaging, a system that measures RNAs and proteins in intact biological samples at subcellular resolution by performing multiple cycles of nucleic acid hybridization of fluorescent molecular barcodes. We demonstrate that spatial molecular imaging has high sensitivity (one or two copies per cell) and very low error rate (0.0092 false calls per cell) and background (~0.04 counts per cell). The imaging system generates three-dimensional, super-resolution localization of analytes at ~2 million cells per sample. Cell segmentation is morphology based using antibodies, compatible with formalin-fixed, paraffin-embedded samples. We measured multiomic data (980 RNAs and 108 proteins) at subcellular resolution in formalin-fixed, paraffin-embedded tissues (nonsmall cell lung and breast cancer) and identified >18 distinct cell types, ten unique tumor microenvironments and 100 pairwise ligand-receptor interactions. Data on >800,000 single cells and ~260 million transcripts can be accessed at http://nanostring.com/CosMx-dataset .


Asunto(s)
Proteínas , ARN , Humanos , Adhesión en Parafina , ARN/genética , Imagen Molecular , Formaldehído
18.
J Phys Chem A ; 115(21): 5335-45, 2011 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-21557584

RESUMEN

Taking the 266 nm excited pyrimidine (uracil or thymine) with cyclopentene as model reaction systems, we have examined the photoproduct formation dynamics from the [2 + 2] photocycloaddition reactions of triplet pyrimidines in solution and provided mechanistic insights into this important DNA photodamage reaction. By combining two compliment methods of nanosecond time-resolved transient IR and UV-vis laser flash-photolysis spectroscopy, the photoproduct formation dynamics as well as the triplet quenching kinetics are measured. Characteristic IR absorption bands due to photoproduct formation have been observed and product quantum yields are determined to be ∼0.91% for uracil and ∼0.41% for thymine. Compared to the measured large quenching rate constants of triplet uracil (1.5 × 10(9) M(-1)s(-1)) or thymine (0.6 × 10(9) M(-1)s(-1)) by cyclopentene, the inefficiency in formation of photoproducts indicates competitive physical quenching processes may exist on the route leading to photoproducts, resulting in very small product yields eventually. Such an energy wasting process is found to be resulted from T(1)/S(0) surface crossings by the hybrid density functional calculations, which compliments the experiments and reveals the reaction mechanism.


Asunto(s)
Pirimidinas/síntesis química , Ciclización , Ciclopentanos/química , Estructura Molecular , Fotoquímica , Pirimidinas/química , Teoría Cuántica , Espectroscopía Infrarroja por Transformada de Fourier
19.
Neuropharmacology ; 199: 108796, 2021 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-34543632

RESUMEN

Our previous study found that low molecular weight chondroitin sulfate (LMWCS) had neuroprotective effects against the toxicity of amyloid-ß (Aß) peptides both in vitro and in vivo, and we speculated that the effects might be related with its anti-oxidative activities. In this study, the anti-Alzheimer's disease (AD) activity of LMWCS was further studied in 5XFAD transgenic mice. After 4-month gavage, the levels of Aß1-42 level, amyloid precursor protein (APP) and presenilin 1 (PS1) were significantly decreased in the brains of 5XFAD mice, indicating the alteration of APP metabolism by LMWCS. Besides, LMWCS inhibited the secretions of pro-inflammatory cytokines, including interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α) and IL-6. Furthermore, the suppression of neuroinflammation by LMWCS was supported by the decreased expressions of glial fibrillary acidic protein (GFAP) and toll-like receptor 2 (TLR2) in the brains. LMWCS also reduced the production of reactive oxygen species (ROS) and the level of phospho-tau (Ser404) in the brains. Nevertheless, the changes in the behavior tests were moderate. In conclusion, LMWCS administration ameliorated APP metabolism, neuroinflammation, ROS production and tau protein abnormality in the brains of 5XFAD mice, displaying the potential to improve the pathological changes of AD mouse brain. LMWCS could be considered as a promising anti-AD drug candidate, nonetheless, the therapy regimen need to be optimized to improve its pharmacotherapy efficacy.


Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/metabolismo , Sulfatos de Condroitina/farmacología , Enfermedades Neuroinflamatorias/tratamiento farmacológico , Enfermedades Neuroinflamatorias/inmunología , Fármacos Neuroprotectores/farmacología , Enfermedad de Alzheimer/inmunología , Péptidos beta-Amiloides/efectos de los fármacos , Precursor de Proteína beta-Amiloide/efectos de los fármacos , Animales , Conducta Animal/efectos de los fármacos , Sulfatos de Condroitina/administración & dosificación , Citocinas/efectos de los fármacos , Modelos Animales de Enfermedad , Ratones , Ratones Transgénicos , Peso Molecular , Enfermedades Neuroinflamatorias/metabolismo , Fármacos Neuroprotectores/administración & dosificación , Estrés Oxidativo/efectos de los fármacos , Presenilina-1/efectos de los fármacos , Proteínas tau/efectos de los fármacos
20.
Sci Rep ; 9(1): 4516, 2019 03 14.
Artículo en Inglés | MEDLINE | ID: mdl-30872641

RESUMEN

Rapid bacterial identification remains a critical challenge in infectious disease diagnostics. We developed a novel molecular approach to detect and identify a wide diversity of bacterial pathogens in a single, simple assay, exploiting the conservation, abundance, and rich phylogenetic content of ribosomal RNA in a rapid fluorescent hybridization assay that requires no amplification or enzymology. Of 117 isolates from 64 species across 4 phyla, this assay identified bacteria with >89% accuracy at the species level and 100% accuracy at the family level, enabling all critical clinical distinctions. In pilot studies on primary clinical specimens, including sputum, blood cultures, and pus, bacteria from 5 different phyla were identified.


Asunto(s)
Bacterias/clasificación , Hibridación de Ácido Nucleico/métodos , ARN Ribosómico 16S/genética , Bacterias/genética , Bacterias/aislamiento & purificación , Bacterias/patogenicidad , Mycobacterium/clasificación , Mycobacterium/genética , Mycobacterium/aislamiento & purificación , Mycobacterium/patogenicidad , Filogenia , Staphylococcus aureus/clasificación , Staphylococcus aureus/genética , Staphylococcus aureus/aislamiento & purificación , Staphylococcus aureus/patogenicidad
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